The present invention relates, in general, to electronics, and more particularly, to methods of forming semiconductor devices and structure.
In the past, the semiconductor industry utilized various methods and structures to form charge pump controllers. Charge pump controllers typically were circuits that stored a charge on capacitors to a voltage and configured the capacitors in parallel or in series to form output voltages that were greater than the input voltage. The charge pump controllers typically operated with a two phase clock where the capacitors were charged during one phase and were connected to supply the output voltage during the second phase. When the amount of current required by the load reduced to a small value, the charge pump controller typically did not accurately regulate the value of the output voltage. Under light load conditions, the output voltage typically had a large ripple voltage that degraded the operation of the load that received the voltage from the charge pump controller. One example of such a charge pump controller was disclosed in the data sheet for a part generally known as an LM2794 that was available from National Semiconductor Inc., of Santa Clara, Calif.
Accordingly, it is desirable to have a charge pump controller that has below ripple voltage.
For simplicity and clarity of the illustration, elements in the figures are not necessarily to scale, and the same reference numbers in different figures denote the same elements. Additionally, descriptions and details of well-known steps and elements are omitted for simplicity of the description. As used herein current carrying electrode means an element of a device that carries current through the device such as a source or a drain of an MOS transistor or an emitter or a collector of a bipolar transistor or a cathode or anode of a diode, and a control electrode means an element of the device that controls current through the device such as a gate of an MOS transistor or a base of a bipolar transistor. Although the devices are explained herein as certain N-channel or P-Channel devices, a person of ordinary skill in the art will appreciate that complementary devices are also possible in accordance with the present invention. It will be appreciated by those skilled in the art that the words during, while, and when as used herein are not exact terms that mean an action takes place instantly upon an initiating action but that there may be some small but reasonable delay, such as a propagation delay, between the reaction that is initiated by the initial action.